Maybe some tools aren't old-fashioned. Maybe they're just perfect. The inevitable tapering toward only the necessary, the honing away of all distraction. The machine at its most simple. After that, what? Easy: mass production.

A razor is a wedge, one of physics' six force-multiplying "simple machines." Unlike the wedge used to split wood or hold a door open, a razor (and its father, the knife) do their work at their tip—the edge.

You know this intrinsically, but consider it again: The sharpest razor is just a few molecules wide at its edge, persuading the molecules it meets that it would be easier to decouple from their mates and let the razor pass through the space where they once twisted and wound together.

So if a razor is such a simple mechanism, why are there so many different types?

Perhaps the razor's simplicity lends itself to many configurations? A screw is a simple object, but there isn't just one type of screw, but countless variations to suit the needs of its user.

I even tossed in a bag of truck-stop stalwarts: The iconic yellow-handled Bic disposable.

But every men's magazine on the planet has reviewed different razors, different shaving creams, different aftershave lotions. And despite this, nearly every man has his own preference, borne of experience or indifference. (When I use a razor I still use a crusty Mach 3 disposable razor that Gillette gifted to every graduating senior in my class, although for the last few years I have used the same Wahl Peanut to shave my neck that I use to trim the beard that I was legally required to grow as a resident of the State of Brooklyn.)

If a razor is a simple machine defined by its microscopic perfection, why not look at it under a microscope?

What I discovered, taking my collection to view under a microscope at University of Oregon's Bio-Optics Laboratory, confirmed what I've long suspected: When fresh from the packaging, even the lowliest Bic razor has an edge that rivals the edge of a hand-honed straight razor. Take a look:

This is the flat edge of a Bic disposable. (The cutting edge is the white line in the middle, the darker section to the white line's right is the upward slope towards flat, unground steel.) You can see that it's manufactured very cleanly, with a relatively clean edge with few nicks or ridges.

The legend shows 100 microns—for reference, a human facial hair is somewhere between 50 and 150 microns thick, depending on your particular genetics. So on average, our 100-micron legend is a good stand-in for the thickness of a human hair. There's little doubt that this cheap Bic will be able to get through at least one hair without issue.

Here's the edge of one of five blades in the Gillette Fusion cartridge. (Although flipped in the other direction as the Bic, getting a clean focus and position for the razor itself was a bit of a hassle.)

It's slightly cleaner than the Bic, although not tremendously so. But there are five of these blades on each razor head, not one, so while the cutting work is distributed more heavily on the front blades, in general the work is spread out between the others.

(That's a Fusion up at the top of the story, too. The legend on that shows 1 millimeter which isn't as useful—I just like the picture.)

Here's a straight razor with finishing oil still on the blade, a Thiers-Issard that is an absolute thing of beauty. Even Jerry Gleason, the even-keeled director of the Bio-Optics lab who I roped into loaning me his microscope, cracked an unscholarly smile when the wood-and-steel Thiers-Issard was taken out of its leather pouch. There's no doubt that the elegance of a straight razor explains much of its lasting appeal.

But look at the edge. It's excellent, but not better than any of our others. Let me quickly qualify: "Stropping" is the process of dragging a straight razor back and forth over a sharpening surface, commonly leather. The Thiers-Issard hadn't been stropped at all before we looked at its edge and I'm certain that in the practiced hands of a straight razor shaver or fleet-handed barber, its edge would have been more perfect.

This is my poor old Mach 3 cartridge, battered and bruised, left to corrode in a drawer for at least a year. It's just mangled—toothy and horrible. Not only is the edge ragged, but you can see where the steel has become pocked for 20 or 30 microns before it gets back to the factory-machined incline.

Which leads me to a very important distinction: On all these shots, we're seeing the edge lengthwise, not straight-on. Because of the challenge of lighting a highly reflective steel surface under a powerful microscope, we weren't able to get any shots where you could distinguish the leading edge from its surrounding material.

No doubt that makes a difference, if not in the cutting edge itself, in the rigidity of the entire blade as it passes through the hair it is designed to cut. The straight razors are solid blades meant to last a lifetime—you could cut through bone with them if you put enough force behind it. The thin blade of the Bic would snap or bend long before you found success at outlaw amputation.

Moreover, the straight razor can easily be brought back to a state of near perfection after each use, while the disposables are subject to whatever wear and tear they undergo before they are eventually tossed out.

In short, I had one totally serviceable shave with the Bic—but I wouldn't want to use the same blade twice.

The frugal man might even come out ahead in the long run with a straight razor, despite the initial outlay of at least a couple hundred dollars, especially considering how much replacement blades from Schick or Gillette cost. Then again, the straight razor shaver will have to spend a few minutes each day taking care of his blade, while the disposable shaver can just toss his old blade in the trash each week. (Or each day, if he wants the same quality shave as the well-tempered straight razor.)

Me? I have to confess: I spent most of the last couple of weeks using the Braun electric, too afraid of the straight razors to actually give them a proper chance. (I am still trying, though, so if you're a straight razor man give me a while to get the hang of it before you call me out.) It's a great electric, too—the way the four different heads actuate make it perhaps the first electric I've ever used that feels like it's actually moving around (and not just over) the contours of my face.

Now if you ever find yourself in another argument about what the best type or razor may be, have confidence in your newfound knowledge that all razors are by their very nature pretty much the same, right down to the edge. Whether you want one tiny plastic strip to replace daily, five blades on a gimbal with a lubricating strip, or a single blade positioned only by the skill in your hand, there's never a bad choice—only dull ones.